圆轨迹SAR快速成像处理

Fast Imaging Processing of Circular SAR

由于圆轨迹SAR特殊的运动轨迹,直线SAR的成像算法不能直接应用于圆轨迹SAR数据处理。然而,对于圆轨迹SAR系统而言,其响应函数具有"沿角度维平移不变"的特性。因此可以利用这一特性,借鉴条带SAR成像算法的思想,在频域研究圆轨迹SAR数据的快速成像方法。该文推导了完全精确的柱面坐标系下圆轨迹SAR回波频谱解析表达式。利用条带SAR成像算法的思想,通过对频谱的合理近似,给出了圆轨迹SAR的快速成像算法。仿真实验验证了算法的有效性。

Because of the special track of circular SAR, the imaging algorithms of SAR in linear track can not be used in processing the circular SAR data directly. However, the response functions of the circular SAR systems can remain the consistency by changing the same aspect angle both of the target and the starting position of the radar. Because of this characteristic, circular SAR can be processed in the azimuth frequency domain by using the fast imaging algorithm of SAR in linear track for reference. In this paper, the exact signal spectrum expressions of circular SAR are derived. By using the reasonable approximations of the exact signal spectrum expressions, the fast imaging algorithms are presented. The simulations show the good performance of the proposed algorithms.